<template>
	<view class="uni-pagination">
		<!-- #ifndef APP-NVUE -->
		<view class="uni-pagination__total is-phone-hide">共 {{ total }} 条</view>
		<!-- #endif -->
		<view class="uni-pagination__btn"
			:class="currentIndex === 1 ? 'uni-pagination--disabled' : 'uni-pagination--enabled'"
			:hover-class="currentIndex === 1 ? '' : 'uni-pagination--hover'" :hover-start-time="20"
			:hover-stay-time="70" @click="clickLeft">
			<template v-if="showIcon === true || showIcon === 'true'">
				<uni-icons color="#666" size="16" type="left" />
			</template>
			<template v-else>
				<text class="uni-pagination__child-btn">{{ prevPageText }}</text>
			</template>
		</view>
		<view class="uni-pagination__num uni-pagination__num-flex-none">
			<view class="uni-pagination__num-current">
				<text class="uni-pagination__num-current-text is-pc-hide"
					style="color:#409EFF">{{ currentIndex }}</text>
				<text class="uni-pagination__num-current-text is-pc-hide">/{{ maxPage || 0 }}</text>
				<!-- #ifndef APP-NVUE -->
				<view v-for="(item, index) in paper" :key="index" :class="{ 'page--active': item === currentIndex }"
					class="uni-pagination__num-tag tag--active is-phone-hide" @click.top="selectPage(item, index)">
					<text>{{ item }}</text>
				</view>
				<!-- #endif -->

			</view>
		</view>
		<view class="uni-pagination__btn"
			:class="currentIndex >= maxPage ? 'uni-pagination--disabled' : 'uni-pagination--enabled'"
			:hover-class="currentIndex === maxPage ? '' : 'uni-pagination--hover'" :hover-start-time="20"
			:hover-stay-time="70" @click="clickRight">
			<template v-if="showIcon === true || showIcon === 'true'">
				<uni-icons color="#666" size="16" type="right" />
			</template>
			<template v-else>
				<text class="uni-pagination__child-btn">{{ nextPageText }}</text>
			</template>
		</view>
	</view>
</template>

<script>
/**
	 * Pagination 分页器
	 * @description 分页器组件，用于展示页码、请求数据等
	 * @tutorial https://ext.dcloud.net.cn/plugin?id=32
	 * @property {String} prevText 左侧按钮文字
	 * @property {String} nextText 右侧按钮文字
	 * @property {Number} current 当前页
	 * @property {Number} total 数据总量
	 * @property {Number} pageSize 每页数据量
	 * @property {Number} showIcon = [true|false] 是否以 icon 形式展示按钮
	 * @event {Function} change 点击页码按钮时触发 ,e={type,current} current为当前页，type值为：next/prev，表示点击的是上一页还是下一个
	 */

import {
  initVueI18n
} from '@dcloudio/uni-i18n'
import messages from './i18n/index.js'
const {
  t
} = initVueI18n(messages)
export default {
  name: 'UniPagination',
  emits: ['update:modelValue', 'input', 'change'],
  props: {
    value: {
      type: [Number, String],
      default: 1
    },
    modelValue: {
      type: [Number, String],
      default: 1
    },
    prevText: {
      type: String
    },
    nextText: {
      type: String
    },
    current: {
      type: [Number, String],
      default: 1
    },
    total: {
      // 数据总量
      type: [Number, String],
      default: 0
    },
    pageSize: {
      // 每页数据量
      type: [Number, String],
      default: 10
    },
    showIcon: {
      // 是否以 icon 形式展示按钮
      type: [Boolean, String],
      default: false
    },
    pagerCount: {
      type: Number,
      default: 7
    }
  },
  data () {
    return {
      currentIndex: 1,
      paperData: []
    }
  },
  computed: {
    prevPageText () {
      return this.prevText || t('uni-pagination.prevText')
    },
    nextPageText () {
      return this.nextText || t('uni-pagination.nextText')
    },
    maxPage () {
      let maxPage = 1
      const total = Number(this.total)
      const pageSize = Number(this.pageSize)
      if (total && pageSize) {
        maxPage = Math.ceil(total / pageSize)
      }
      return maxPage
    },
    paper () {
      const num = this.currentIndex
      // TODO 最大页数
      const pagerCount = this.pagerCount
      // const total = 181
      const total = this.total
      const pageSize = this.pageSize
      const totalArr = []
      const showPagerArr = []
      const pagerNum = Math.ceil(total / pageSize)
      for (let i = 0; i < pagerNum; i++) {
        totalArr.push(i + 1)
      }
      showPagerArr.push(1)
      const totalNum = totalArr[totalArr.length - (pagerCount + 1) / 2]
      totalArr.forEach((item, index) => {
        if ((pagerCount + 1) / 2 >= num) {
          if (item < pagerCount + 1 && item > 1) {
            showPagerArr.push(item)
          }
        } else if (num + 2 <= totalNum) {
          if (item > num - (pagerCount + 1) / 2 && item < num + (pagerCount + 1) / 2) {
            showPagerArr.push(item)
          }
        } else {
          if ((item > num - (pagerCount + 1) / 2 || pagerNum - pagerCount < item) && item < totalArr[
            totalArr.length - 1]) {
            showPagerArr.push(item)
          }
        }
      })
      if (pagerNum > pagerCount) {
        if ((pagerCount + 1) / 2 >= num) {
          showPagerArr[showPagerArr.length - 1] = '...'
        } else if (num + 2 <= totalNum) {
          showPagerArr[1] = '...'
          showPagerArr[showPagerArr.length - 1] = '...'
        } else {
          showPagerArr[1] = '...'
        }
        showPagerArr.push(totalArr[totalArr.length - 1])
      } else {
        if ((pagerCount + 1) / 2 >= num) {} else if (num + 2 <= totalNum) {} else {
          showPagerArr.shift()
          showPagerArr.push(totalArr[totalArr.length - 1])
        }
      }

      return showPagerArr
    }
  },
  watch: {
    current: {
      immediate: true,
      handler (val, old) {
        if (val < 1) {
          this.currentIndex = 1
        } else {
          this.currentIndex = val
        }
      }
    },
    value: {
      immediate: true,
      handler (val) {
        if (Number(this.current) !== 1) return
        if (val < 1) {
          this.currentIndex = 1
        } else {
          this.currentIndex = val
        }
      }
    }
  },
  methods: {
    // 选择标签
    selectPage (e, index) {
      if (parseInt(e)) {
        this.currentIndex = e
        this.change('current')
      } else {
        const pagerNum = Math.ceil(this.total / this.pageSize)
        // let pagerNum = Math.ceil(181 / this.pageSize)
        // 上一页
        if (index <= 1) {
          if (this.currentIndex - 5 > 1) {
            this.currentIndex -= 5
          } else {
            this.currentIndex = 1
          }
          return
        }
        // 下一页
        if (index >= 6) {
          if (this.currentIndex + 5 > pagerNum) {
            this.currentIndex = pagerNum
          } else {
            this.currentIndex += 5
          }
        }
      }
    },
    clickLeft () {
      if (Number(this.currentIndex) === 1) {
        return
      }
      this.currentIndex -= 1
      this.change('prev')
    },
    clickRight () {
      if (Number(this.currentIndex) >= this.maxPage) {
        return
      }
      this.currentIndex += 1
      this.change('next')
    },
    change (e) {
      this.$emit('input', this.currentIndex)
      this.$emit('update:modelValue', this.currentIndex)
      this.$emit('change', {
        type: e,
        current: this.currentIndex
      })
    }
  }
}
</script>

<style lang="scss" scoped>
	$uni-primary: #2979ff;
	.uni-pagination {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		position: relative;
		overflow: hidden;
		flex-direction: row;
		justify-content: center;
		align-items: center;
	}

	.uni-pagination__total {
		font-size: 14px;
		color: #999;
		margin-right: 15px;
	}

	.uni-pagination__btn {
		/* #ifndef APP-NVUE */
		display: flex;
		cursor: pointer;
		/* #endif */
		padding: 0 8px;
		line-height: 30px;
		font-size: 12px;
		position: relative;
		background-color: #F0F0F0;
		flex-direction: row;
		justify-content: center;
		align-items: center;
		text-align: center;
		border-radius: 5px;
		// border-width: 1px;
		// border-style: solid;
		// border-color: $uni-border-color;
	}

	.uni-pagination__child-btn {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		font-size: 12px;
		position: relative;
		flex-direction: row;
		justify-content: center;
		align-items: center;
		text-align: center;
		color: #666;
		font-size: 12px;
	}

	.uni-pagination__num {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		flex: 1;
		flex-direction: row;
		justify-content: center;
		align-items: center;
		height: 30px;
		line-height: 30px;
		font-size: 12px;
		color: #666;
		margin: 0 5px;
	}

	.uni-pagination__num-tag {
		/* #ifdef H5 */
		cursor: pointer;
		min-width: 30px;
		/* #endif */
		margin: 0 5px;
		height: 30px;
		text-align: center;
		line-height: 30px;
		// border: 1px red solid;
		color: #999;
		border-radius: 4px;
		// border-width: 1px;
		// border-style: solid;
		// border-color: $uni-border-color;
	}

	.uni-pagination__num-current {
		/* #ifndef APP-NVUE */
		display: flex;
		/* #endif */
		flex-direction: row;
	}

	.uni-pagination__num-current-text {
		font-size: 15px;
	}

	.uni-pagination--enabled {
		color: #333333;
		opacity: 1;
	}

	.uni-pagination--disabled {
		opacity: 0.5;
		/* #ifdef H5 */
		cursor: default;
		/* #endif */
	}

	.uni-pagination--hover {
		color: rgba(0, 0, 0, 0.6);
		background-color: #eee;
	}

	.tag--active:hover {
		color: $uni-primary;
	}

	.page--active {
		color: #fff;
		background-color: $uni-primary;
	}

	.page--active:hover {
		color: #fff;
	}

	/* #ifndef APP-NVUE */
	.is-pc-hide {
		display: block;
	}

	.is-phone-hide {
		display: none;
	}

	@media screen and (min-width: 450px) {
		.is-pc-hide {
			display: none;
		}

		.is-phone-hide {
			display: block;
		}

		.uni-pagination__num-flex-none {
			flex: none;
		}
	}

	/* #endif */
</style>
